Pneumatic shuttle picking mechanism

Abstract

A pneumatic picking mechanism for weaving shuttles wherein the weaving shuttle is driven by a piston moved in a cylinder cavity by pressurized gas and wherein the pressurized gas is supplied from a reservoir through a main valve to the cylinder cavity and the main valve is controlled via a control valve assisted by an auxiliary valve.

What is claimed is: 
     
       1. A pneumatic shuttle picking mechanism compromising: a cylinder defining a cavity;   a piston disposed within said cavity of said cylinder and adapted to be driven by pressurized gas;   a piston rod connected to said cylinder and adapted to be connected to a shuttle for driving the shuttle;   a main valve for controlling the feeding of pressurized gas from a reservoir to said cylinder, said main valve including: a valve seat; a valve guide; a slidably mounted valve disk adapted to bear against the valve seat when said main valve is in a closed position, said valve disk having a valve stem slidably supported in the valve guide and said valve disk being shaped like a cap with a hollow rear side, the annular rim of said hollow rear side of said valve disk bearing substantially tightly against the outer periphery of the valve guide to form between the rear side of said valve disk and the front side of said valve guide a chamber whose volume changes with movement of the valve disk and which reaches a maximum when said main valve is in the closed position;   an auxiliary valve moving said valve disk by establishing a pressure differential between the front and rear sides of said valve disk, said auxiliary valve being slidably mounted in a through-bore in said valve stem of said value disk, and in its forward position communicating said chamber through the rear opening of said through-bore with said reservoir and, in its rearward position, communicating the chamber with said cavity, the arrangement being such that, when said main valve is closed and said piston is in its rearward starting position, said auxiliary valve is urged away from said piston into its rearward position; and   a control valve for providing coupling with a control port which is located at the transition from said valve seat to said cavity, said control valve connecting said control port with said reservoir to open said main valve and to strike the shuttle, or connecting said control port with a source of gas under pressure substantially lower than the operating pressure prevailing in said reservoir to close said main valve and to brake the arriving shuttle, or connecting said control port with a vacuum source to return said piston with said main valve in its closed position.   
     
     
       2. A shuttle picking mechanism according to claim 1 wherein: said valve seat and said valve disk have sealing faces conically flaring toward said reservoir; and   an O-ring is disposed in an annular groove formed in the wide end of the valve seat.   
     
     
       3. A shuttle picking mechanism according to claim 2 wherein: said auxiliary valve includes a stem and an enlargement in the central region of said stem; and   said chamber is connected to the through-bore in the valve stem of said valve disk through connecting openings.   
     
     
       4. A shuttle picking mechanism according to claim 1 wherein: said auxiliary valve includes a stem and an enlargement in the central region of said stem; and   said chamber is connected to the through-bore in the valve stem of said valve disk through connecting openings.   
     
     
       5. A shuttle picking mechanism according to claim 1 further comprising: a catch hook mounted at the forward end of said piston rod for coupling a shuttle to the forward end of said piston rod, said catch hook being adapted to be lifted by a control cam arranged in the region of the forward end position of said piston rod to thereby disengage the shuttle.   
     
     
       6. A shuttle picking mechanism according to claim 2 further comprising: a catch hook mounted at the forward end of said piston rod for coupling a shuttle to the forward end of said piston rod, said catch hook being adapted to has lifted by a control cam arranged in the region of the forward end position of said piston rod to thereby disengage the shuttle.   
     
     
       7. A shuttle picking mechanism according to claim 3 further comprising: a catch hook mounted at the forward end of said piston rod for coupling a shuttle to the forward end of said piston rod, said catch hook being adapted to has lifted by a control cam arranged in the region of the forward end position of said piston rod to thereby disengage the shuttle.   
     
     
       8. A shuttle picking mechanism according to claim 4 further comprising: a catch hook mounted at the forward end of said piston rod for coupling a shuttle to the forward end of said piston rod, said catch hook being adapted to has lifted by a control cam arranged in the region of the forward end position of said piston rod to thereby disengage the shuttle.